For years, a class of abrasive articles known generically as “structured abrasive articles” has been sold commercially for use in surface finishing. Structured abrasive articles have a topographically structured abrasive layer affixed to a backing, and are often used in conjunction with a liquid such as, for example, water, optionally containing surfactant. The topographically structured abrasive layer has a plurality of shaped abrasive composites (typically having minute size), each having abrasive particles dispersed a binder. In many cases, the shaped abrasive composites are precisely-shaped, for example, according to various geometric shapes (e.g., pyramids). Examples of such structured abrasive articles include those marketed under the trade designation “TRIZACT” by 3M Company, St. Paul, Minn., and which are used in the automotive industry to remove defects in automotive clear coats (e.g., as available under the trade designation “466LA-3M TRIZACT FINESSE-IT FILM”) based on urethane, acrylate, or silicate based chemistries.
Structured abrasive articles are often used in combination with a backup pad mounted to a tool (e.g., a disk sander or a random orbit sander). In such applications, structured abrasive articles typically have an attachment interface layer (e.g., a hooked film, looped fabric, or adhesive) that affixes them to the back up pad during use.
Many structured abrasive articles are known to lack aggressive cut upon initial use, with improvements in cut seen with continued use. This can occur because the abrasive particles are buried in the binder within the body of the abrasive composite and are not available for abrading. One technique used in the art for addressing the problem of lower initial cut has been to abrade the abrasive surface of the structured abrasive article, prior to its initial use, using another coated abrasive article such as sandpaper.
The cut performance of current products is very sensitive to the type of workpiece coating materials, which may be based on various kinds of technologies such as polyurethane, acrylate, powder coatings, or even silicate based hard coatings reinforced with nanoparticles.